The structure of the steroidal bromosapogenins

Abstract

In contrast to the 25R-sapogenins, which yield two isomeric monobromo-derivatives, the 25S-sapogenins yield only single monobromo-derivatives. Infrared absorption, proton magnetic resonance, and X-ray crystallographic measurements on certain of these compounds are reported, and the conclusions to be drawn as to steric configuration are discussed. It is agreed that 23a- and 23b-bromo-25R-sapogenins have bromine in equatorial and axial positions, respectively. In 23-bromo-25S-sapogenins the bromine is equatorial. 23,23-Dibromo- and 23-iododerivatives of certain sapogenins and a series of deutero-derivatives have been prepared.